motif discovery for small set of genes

Question

[Calangoa]

Hi there, I am not familiar with motif discovery and I have a question, I have a small set of genes extracted from microarray data and I want to know transcription factors binding site and finding motifs for these small number(27 genes) with Opossum. the first question is that is motif discovery logical for a small set of genes? if so would it good to divide genes to two list, repressed genes and activate genes and then finding motifs to find the better result?

[ATpoint]

Where are these motifs supposed to be? You have microarray data, not sequences. Do you want motifs in the promoter regions? Your question is unclear.